Stroller

ABSTRACT

Embodiments include, but are not limited to, a stroller with a collapsible frame where an upper end of the side armrest rotatably connected to a slider, the lower end of the side armrest rotatably connected to an upper end of the rear leg set, a middle portion of the rear leg set rotatably connected to a lower end of the handlebar set, the upper end of the rear leg set and the lower end of the side armrest rotatably connected to the upper end of the front leg set, the middle portion of the front leg set rotatably connected to the front end of the seat set, the rear end of the seat set rotatably connected to the lower end of the handlebar set, and the slider capable of sliding along the length of the handlebar set, wheel assemblies, and a locking mechanism, between the handlebar set and the slider.

CROSS REFERENCE

This application claims priority from and is a U.S. national phasefiling of PCT Application No. PCT/CN2019/077331, filed Mar. 7, 2019,which in turn claims priority from Chinese Application No.CN201810647800.0, filed Jun. 22 2018, now granted Chinese Patent No.CN108860280, issued Nov. 23, 2018; Chinese Application No.201810186731.8, filed Mar. 7, 2018; now granted Chinese Patent No.CN108275192; Chinese Application No. 201820312244.7, filed Mar. 7, 2018,now granted Chinese Patent No. CN207931790, issued Oct. 2, 2018; and PCTApplication No. PCT/CN2018/094789, filed Jul. 6, 2018, expired, all ofwhich are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The technical field relates to mechanical, wheeled devices including astroller, and more particularly to a stroller that is convenientlyfolded.

BACKGROUND

A stroller is a functional carriage designed to facilitate the outdooractivities of a baby or other small item, greatly reducing the burden ofcarrying the baby or other small item when going out. In order tofacilitate carrying and transportation, conventional strollers aregenerally foldable in order to reduce space occupation. However, mostconventional strollers still have the following defects: 1. They cannotbe fully folded and still occupy a large space after being folded, whichis not conducive to carrying and transporting; 2. The structure iscomplex and the production cost is high. 3. Most conventional strollersneed to be collapsed manually, and the collapsing operation is rathercomplicated.

Therefore, it is necessary to design a novel stroller to solve thedefects in the prior art.

SUMMARY

An objective of the present invention is to address the defects of theprior art, thereby providing a stroller that has a small size and asimple structure. In order to achieve the above objective, the presentinvention adopts the following technical solution:

a stroller, comprising: a frame that can be collapsed from an unfoldedstate to a folded state, the frame comprising a front leg set, a rearleg set, a seat set, a side armrest, a handlebar set, and a slider, theupper end of the side armrest being rotatably connected to the slider,the lower end of the side armrest being rotatably connected to the upperend of the rear leg set, the middle portion of the rear leg set beingrotatably connected to the lower end of the handlebar set, at least oneof the upper end of the rear leg set and the lower end of the sidearmrest being rotatably connected to the upper end of the front leg set,the middle portion of the front leg set being rotatably connected to thefront end of the seat set, the rear end of the seat set being rotatablyconnected to the lower end of the handlebar set, in particular via aconnecting member, and the slider being capable of sliding along thelength of the handlebar set; a front wheel assembly, disposed at a frontportion of the bottom of the frame; a rear wheel assembly, disposed at arear portion of the bottom of the frame; and a locking mechanism (alsoreferred to as locking assembly), disposed between the handlebar set andthe slider, the locking mechanism being provided for locking the framein an unfolded state.

In some aspects of the embodiments disclosed herein, a stroller, mayinclude a frame, which is collapsible from an unfolded state to a foldedstate, the frame comprising a front leg set, a rear leg set, a seat set,a side armrest, a handlebar set, and a slider, the upper end of the sidearmrest being rotatably connected to the slider, the lower end of theside armrest being rotatably connected to the upper end of the rear legset, the middle portion of the rear leg set being rotatably connected tothe lower end of the handlebar set, at least one of the upper end of therear leg set and the lower end of the side armrest being rotatablyconnected to the upper end of the front leg set, the middle portion ofthe front leg set being rotatably connected to the seat set, the rearend of the seat set being rotatably connected to the lower end of thehandlebar set, in particular via a connecting member, and the sliderbeing capable of sliding along the length of the handlebar set, a frontwheel assembly, disposed at a front portion of the bottom of the frame;

a rear wheel assembly, disposed at a rear portion of the bottom of theframe, and a locking mechanism, disposed between the handlebar set andthe slider, the locking mechanism being configured to lock the frame inan unfolded state. In some examples, the stroller includes the lockingmechanism with a locking pin and a locking hole, the locking pin beingdisposed on the handlebar set, the locking hole being disposed in theslider, the frame being in a locked state when the locking pin isinserted into the locking hole, and the frame being in an unlocked statewhen the locking pin is disengaged from the locking hole.

In some examples, the locking pin includes a stopper portion and alocking portion that extends laterally from the stopper portion, thelocking portion being inserted into the locking hole, and the stopperportion being limited to one side of the locking hole.In some examples, the handlebar set includes an upper handlebar set anda lower handlebar set, and a joint head disposed between the upperhandlebar set and the lower handlebar set. In some examples, the lockingmechanism further includes a spring, a central portion of the lockingportion is provided with a cylindrical support portion, the lockingportion is recessed with an accommodating space, the lower handlebar setcomprises an insert, one end of the spring extends into theaccommodating space and abuts against the cylindrical support portion,and the other end of the spring abuts against the insert.In some examples, the locking mechanism further includes a cord, inparticular a steel cord, one end of the cord being connected to thelocking pin, the other end of the cord being connected to the jointhead.In some examples, the handlebar set further includes the connectingmember connected to the lower end of the lower handlebar set, and therear end of the seat set is rotatably connected to the connectingmember. In some examples, the frame further includes a backrest bar, thebackrest bar being rotatably connected to the connecting member.In some examples, the upper end of the rear leg set is rotatablyconnected to the upper end of the front leg set, and the upper end ofthe front leg set is not rotatably connected to the lower end of theside armrest.In some examples, the upper end of the front leg set is rotatablyconnected to the lower end of the side armrest, and the upper end of thefront leg set is not rotatably connected to the upper end of the rearleg set.

In some examples, the upper end of the front leg set, the upper end ofthe rear leg set, and the lower end of the side armrest are coaxiallyhinged. In some examples, the middle portion of the front leg set isrotatably connected to the seat set, in particular to the front end orto a middle portion of the seat set.

Some example embodiments include an automatically collapsible strollerframe, that includes a front leg set (11), the front leg set (11)comprising a front leg bar (111), a rear leg set (12), the rear leg set(12) comprising a rear leg bar (121), a handlebar set (15), thehandlebar set (15) comprising a lower handlebar tube (152) and aU-shaped upper handlebar tube (151) that is rotatably disposed at anupper end of the lower handlebar tube (152), the lower handlebar tube(152) being provided with a slider (16) that is slidable along its axialdirection, a locking assembly (4) being provided between the lowerhandlebar tube (152) and the slider (16) for locking or unlocking theslider (16), the lower end of the lower handlebar tube (152) beinghinged to the middle portion of the rear leg bar (121), a transmissionmember (14) being hinged between the slider (16) and the upper portionof the rear leg bar (121), and the upper end of the front leg bar (111)being hinged to the lower end of the transmission member (14) and/or theupper end of the rear leg bar (121), and an elastic member (43), theelastic member (43) being disposed between the front leg bar (111) andthe rear leg bar (121) such that when the stroller frame collapses, thefront leg bar (111) and the rear leg bar (121) are automatically broughtclose together under the elastic pulling of the elastic member (43),thereby completing automatic collapsing. In some examples, a seat set(13), the front portion of the seat set (13) being hinged to the middleportion of the front leg bar (111), the rear end of the seat set (13)being hinged to the lower end of the lower handlebar tube (152), inparticular via a connecting base (154), and the front end of the elasticmember (43) being fixed to the seat set (13), in particular fixed to afront portion or to a middle portion of the seat set. In some examples,further including where the connecting base (154) being connected to thelower end of the lower handlebar tube (152) which is hinged to themiddle portion of the rear leg bar (121). In some examples, furtherincluding a backrest set (9), the backrest set (9) including a U-shapedbackrest bar (91), the end of the backrest bar (91) being hinged to theconnecting base (154). In some examples, the rear end of the elasticmember (43) is fixed to the connecting base (154) or directly fixed tothe rear leg bar (121). In some examples, the locking assembly (4)includes a locking pin (41) disposed in the lower handlebar tube (152)and a locking hole (42) disposed in the slider (16), and the locking pin(41) can penetrate the lower handlebar tube (152) and be elasticallyengaged in the locking hole (42). In some examples, further including arotating base (153) is disposed between the lower handlebar tube (152)and the upper handlebar tube (151), and a pull cord is disposed betweenthe rotating base (153) and the locking pin (41). In some examples, theupper handlebar tube (151) is provided with an unlocking member (50) forunlocking or locking the upper handlebar tube (151) so that it isrotatable or fixable relative to the lower handlebar tube (152). In someexamples, the upper end of the front leg bar (111), the lower end of thetransmission member (14) and the upper end of the rear leg bar (121) arecoaxially hinged. In some examples, the upper end of the front leg bar(111) is hinged to the upper end of the rear leg bar (121) and is nothinged to the lower end of the transmission member (14). In someexamples, the upper end of the front leg bar (111) is hinged to thelower end of the transmission member (14) and is not hinged to the upperend of the rear leg bar (121). In some examples, the elastic member (43)is a spring or rubber band.

In some example embodiments, a stroller, including a frame which iscollapsible from an unfolded state to a folded state, the frame includesa front leg set, a rear leg set,

a seat set,

a side armrest,

a handlebar set, and

a slider, the upper portion of the side armrest being rotatablyconnected to the slider, the lower portion of the side armrest beingrotatably connected to the front leg set or to the rear leg set, therear leg set being rotatably connected to the lower portion of thehandlebar set, at least one of the rear leg set and the side armrestbeing rotatably connected to the front leg set, the front leg set beingrotatably connected to the seat set, the seat set being rotatablyconnected to the lower portion of the handlebar set, in particular via aconnecting member, the slider being capable of sliding along thehandlebar set, a front wheel assembly, disposed at a front portion ofthe bottom of the frame, a rear wheel assembly, disposed at a rearportion of the bottom of the frame, and a locking mechanism, disposedbetween the handlebar set and the slider, the locking mechanism beingconfigured to lock the frame in an unfolded state. In some examples, thelower end of the side armrest being rotatably connected to the upper endof the rear leg set. In some examples, the rear leg set being rotatablyconnected to the lower end of the handlebar set. In some examples, themiddle portion of the rear leg set being rotatably connected to thelower end of the handlebar set. In some examples, at least one of theupper end of the rear leg set and the lower end of the side armrestbeing rotatably connected to the upper end of the front leg set. In someexamples, the middle portion of the front leg set being rotatablyconnected to the seat set. In some examples, the rear end of the seatset being rotatably connected to the lower end of the handlebar set. Insome examples, the locking mechanism comprises a locking pin and alocking hole, the locking pin being disposed on the handlebar set, thelocking hole being disposed in the slider, the frame being in a lockedstate when the locking pin is inserted into the locking hole, and theframe being in an unlocked state when the locking pin is disengaged fromthe locking hole. In some examples, the handlebar set comprises an upperhandlebar set and a lower handlebar set, and a joint head disposedbetween the upper handlebar set and the lower handlebar set. In someexamples, the locking mechanism further comprises a spring, a centralportion of a locking portion is provided with a cylindrical supportportion, the locking portion is recessed with an accommodating space,the lower handlebar set comprises an insert, one end of the springextends into the accommodating space and abuts against the cylindricalsupport portion, and the other end of the spring abuts against theinsert. In some examples, the locking mechanism further comprises alinkage member, in particular a pull cord, more in particular a steelcord, one end of the linkage member being connected to the locking pin,the other end of the linkage member being connected to the joint head.In some examples, the handlebar set further comprises the connectingmember connected to a lower portion of the lower handlebar set, themiddle portion of the rear leg set is rotatably connected to theconnecting member via the lower portion of the lower handlebar set, andthe rear portion of the seat set is rotatably connected to theconnecting member. In some examples, the upper portion of the rear legset is rotatably connected to the upper portion of the front leg set,and the upper portion of the front leg set is not rotatably connected tothe lower portion of the side armrest. In some examples, the upperportion of the front leg set is rotatably connected to the lower portionof the side armrest, and the upper portion of the front leg set is notrotatably connected to the upper end of the rear leg set. In someexamples, the upper end of the front leg set, the upper end of the rearleg set, and the lower end of the side armrest are coaxially hinged. Insome examples, the middle portion of the front leg set is rotatablyconnected to the seat set, in particular to the front end or to a middleportion of the seat set.

In some example embodiments, a collapsible stroller frame, is describedthat includes a front leg set (11), the front leg set (11) comprising afront leg bar (111), a rear leg set (12), the rear leg set (12)comprising a rear leg bar (121), a handlebar set (15) being providedwith a slider (16) that is slidable along its axial direction, a lockingassembly (4) being provided between the handlebar set (15) and theslider (16) for locking or unlocking the slider (16), the handlebar set(15) being hinged to the rear leg bar (121), a transmission member (14)being hinged between the slider (16) and the rear leg bar (121) or thefront leg bar (111), and an elastic member (43) being associated withthe front leg bar (111) and the rear leg bar (121) such that when thestroller frame collapses, the front leg bar (111) and the rear leg bar(121) are brought close together under the elastic pulling of theelastic member (43), thereby completing the collapsing. In someexamples, the handlebar set (15) comprising a lower handlebar tube (152)and an upper handlebar tube (151) that is rotatably disposed at an upperend of the lower handlebar tube (152), the lower handlebar tube (152)being provided with the slider (16) that is slidable along its axialdirection. In some examples, the locking assembly (4) being providedbetween the lower handlebar tube (152) and the slider (16). In someexamples, the lower handlebar tube (152) being hinged to the rear legbar (121), In some examples, the upper handlebar tube (151) is U-shaped.In some examples, the lower end of the lower handlebar tube (152) beinghinged to the rear leg bar (121), in particular to a middle portionthereof. In some examples, the transmission member (14) being hingedbetween the slider (14) on the one hand and the upper portion of therear leg bar (121) or the upper portion of the front leg bar (111) onthe other hand.

In some examples, the upper end of the front leg bar (111) being hingedto the lower end of the transmission member (14) and/or the upper end ofthe rear leg bar (121). In some examples, the stroller frame isautomatically collapsible, wherein the front leg bar (111) and the rearleg bar (121) are automatically brought close together under the elasticpulling of the elastic member (43), thereby completing the collapsing.In some examples, it further includes a seat set (13), the seat set (13)being hinged to the front leg bar (111), the seat set (13) being hingedto the lower end of the lower handlebar tube (152), in particular via aconnecting base (154). In some examples, the front end of the elasticmember (43) being fixed to the seat set (13), in particular fixed to afront portion or to a middle portion of the seat set (13). In someexamples, the front portion of the seat set (13) being hinged to themiddle portion of the front leg bar (111). In some examples, the rearend of the seat set (13) being hinged to the lower end of the lowerhandlebar tube (152), in particular via the connecting base (154). Insome examples, the connecting base (154) being connected to the lowerend of the lower handlebar tube (152) which is hinged to the middleportion of the rear leg bar (121). In some examples, further includes abackrest set (9), the backrest set (9) comprising a U-shaped backrestbar (91), the end of the backrest bar (91) being hinged to theconnecting base (154). In some examples, the rear end of the elasticmember (43) is directly or indirectly fixed to the connecting base (154)or directly fixed to the rear leg bar (121). In some examples, thelocking assembly (4) comprises a locking pin (41) disposed in the lowerhandlebar tube (152) and a locking hole (42) disposed in the slider(16), and the locking pin (41) can penetrate the lower handlebar tube(152) and be elastically engaged in the locking hole (42). In someexamples, further including a rotating base (153) is disposed betweenthe lower handlebar tube (152) and the upper handlebar tube (151), and apull cord is disposed between the rotating base (153) and the lockingpin (41). In some examples, the upper handlebar tube (151) is providedwith an unlocking member (50) for unlocking or locking the upperhandlebar tube (151) so that it is rotatable or fixable relative to thelower handlebar tuber (152). In some examples, the upper end of thefront leg bar (111), the lower end of the transmission member (14) andthe upper end of the rear leg bar (121) are coaxially hinged. In someexamples, the upper end of the front leg bar (111) is hinged to theupper end of the rear leg bar (121) and is not hinged to the lower endof the transmission member (14). In some examples, the upper end of thefront leg bar (111) is hinged to the lower end of the transmissionmember (14) and is not hinged to the upper end of the rear leg bar,(121). In some examples, the elastic member (43) is a spring or rubberband.

In some example aspects, the embodiments have the following examplebeneficial effects: after the locking mechanism is unlocked, the frameof the stroller can be collapsed from an unfolded state to a foldedstate, and the front leg set, the rear leg set, the seat set, the sidearmrest, and the handlebar set can be relatively rotated; thus, theframe of the stroller is fully folded to reduce the space occupied bythe stroller, allowing easy carrying and transportation. In addition,the present invention has the advantages of a simple structure, easyproduction and assembly, and a low production cost.

In some example aspects, the technical problem to be solved by thepresent invention is to provide an automatically collapsible strollerframe to make the collapsing operation more convenient and faster.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific example, non-limiting embodiments are further described indetail below with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of the frame of the present invention in anunfolded state;

FIG. 2 is a lateral view of the frame of the present invention in anunfolded state;

FIG. 3 is a schematic view of the process of folding the frame of thepresent invention;

FIG. 4 is a perspective view of the frame of the present invention in afolded state;

FIG. 5 is a front view of the frame of the present invention in anunfolded state;

FIG. 6 is a cross-sectional view taken along line A-A of FIG. 5 and anenlarged view of the locking mechanism in the locked state;

FIG. 7 is a schematic view of the locking pin and spring of the presentinvention;

FIG. 8 is a schematic view of the upper handlebar set of the presentinvention when folded;

FIG. 9A is a cross-sectional view taken along line B-B of FIG. 8 and anenlarged view of the locking mechanism in the unlocked state;

FIG. 9B is a further enlarged view of the locking mechanism in theunlocked state;

FIG. 10 is a perspective view and a partial enlarged view of the frameof the present invention and the backrest bar;

FIG. 11 is a schematic view showing an example embodiment of theconnection relationship between the front leg set, the rear leg set, andthe side armrest according to the present invention;

FIG. 12 is a schematic view showing an example embodiment of theconnection relationship between the front leg set, the rear leg set, andthe side armrest according to the present invention;

FIG. 13 is a schematic view showing a third embodiment of the connectionrelationship between the front leg set, the rear leg set, and the sidearmrest according to the present invention.

FIG. 14 is an example structural diagram of the present invention whenit is unfolded;

FIG. 15 is another example structural diagram of the present inventionwhen it is unfolded;

FIG. 16 is a structural view of the present invention when the strollercollapses;

FIG. 17 is a structural view of the present invention after collapsingof the stroller;

FIG. 18 is a cross-sectional view of the locking assembly of the presentinvention in the locked state;

FIG. 19A is a cross-sectional view of the locking assembly of thepresent invention in an unlocked state;

FIG. 19B is a further enlarged view of the locking assembly in theunlocked state;

FIG. 20 is a schematic diagram showing the configuration in which theupper end of the front leg bar, the lower end of the transmissionmember, and the upper end of the rear leg bar are coaxially hinged;

FIG. 21 is a schematic view showing the configuration in which the upperend of the front leg bar is hinged to the upper end of the rear leg barand is not hinged to the lower end of the transmission member; and

FIG. 22 is a schematic view showing the configuration in which the upperend of the front leg bar is hinged to the lower end of the transmissionmember and is not hinged to the upper end of the rear leg bar.

Example descriptions of the reference numerals, none of which areintended to be limiting, but merely an example: Frame 1; Front leg set11; Front leg bar 111; Rear leg set 12; Rear leg bar 121; Seat set 13;Side armrest/Transmission member 14; Handlebar set 15; Upper handlebarset 151; Lower handlebar set 152; Insert 1521; Joint head 153;Connecting member 154; Tooth portion 1541; Slider 16; Backrest set 9;Backrest bar 91; Front wheel assembly 2; Rear wheel assembly 3; Lockingmechanism 4; Locking pin 41; Stopper portion 411; Locking portion 412;Cylindrical support portion 4121; Accommodating space 4122; Locking hole42; Spring 43; Unlocking member 50; Pull cord 60, none of which areintended to be limiting, but merely an example.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea sufficient understanding of the subject matter presented herein. Butit will be apparent to one of ordinary skill in the art that the subjectmatter may be practiced without these specific details. Moreover, theparticular embodiments described herein are provided by way of exampleand should not be used to limit the scope of the disclosures to theseparticular embodiments.

One example aspect of the present invention will be further describedbelow with reference to the drawings and specific embodiments in orderto facilitate a better understanding of the objective, structure,characteristics, and effects of the present invention.

As shown in FIG. 1 and FIG. 2, a stroller according to a preferredembodiment of the present invention comprises a frame 1, a front wheelassembly 2 disposed at a front portion of the bottom of the frame 1, arear wheel assembly 3 disposed at a rear portion of the bottom of theframe 1, and a locking mechanism 4 disposed on the frame 1.

As shown in FIGS. 1 to 4, the frame 1 can be collapsed from an unfoldedstate to a folded state. The frame 1 comprises a front leg set 11, arear leg set 12, a seat set 13, a side armrest 14, a handlebar set 15,and a slider 16. The upper portion of the side armrest 14 is rotatablyconnected to the slider 16. The lower portion of the side armrest 14 isrotatably connected to the front leg set 11 or to the rear leg set 12.The rear leg set 12 is rotatably connected to the lower portion of thehandlebar set 15. At least one of the rear leg set 12 and the sidearmrest 14 is rotatably connected to the front leg set 11. The front legset 11 is rotatably connected to the seat set 13. The seat set 13 isrotatably connected to the lower portion of the handlebar set 15, inparticular via a connecting member 154. The slider 16 is capable ofsliding along the handlebar set 15.

In an embodiment, the upper end of the side armrest 14 is rotatablyconnected to the slider 16. The lower end of the side armrest 14 isrotatably connected to the upper end of the rear leg set 12. The rearleg set 12, in particular the middle portion of the rear leg set, isrotatably connected to the lower end of the handlebar set 15.

At least one of the upper end of the rear leg set 12 and the lower endof the side armrest 14 is rotatably connected to the upper end of thefront leg set 11. In this embodiment, the upper end of the rear leg set12, the lower end of the side armrest 14, and the upper end of the frontleg set 11 are coaxially hinged, and their connection relationship isshown in FIG. 11. The middle portion of the front leg set 11 isrotatably connected to the seat set 13, in particular to the front endor to a middle portion of the seat set 13, and the rear end of the seatset 13 is rotatably connected to the lower end of the handlebar set 15,in particular via the connecting member 154. The slider 16 can be slidalong the length of the handlebar set 15. In the present embodiment, thefront wheel assembly 2 is rotatably connected to the lower end of thefront leg set 11, and the rear wheel assembly 3 is rotatably connectedto the lower end of the rear leg set 12.

As shown in FIG. 6, the locking mechanism 4 is provided between thehandlebar set 15 and the slider 16, and the locking mechanism 4 isconfigured to lock the frame 1 in an unfolded state. After the lockingmechanism 4 is unlocked, the frame 1 of the stroller can be collapsedfrom an unfolded state to a folded state. The front leg set 11, the rearleg set 12, the seat set 13, the side armrest 14, and the handlebar set15 can be relatively rotated. Thus, the frame 1 of the stroller is fullyfolded to reduce the space occupied by the stroller, allowing easycarrying and transportation. The present invention has a simplestructure, is easy to produce and assemble, and has a low productioncost.

As shown in FIG. 1, in the present embodiment, the front wheel assembly2 is rotatably connected to the lower end of the front leg set 11, andthe rear wheel assembly 3 is rotatably connected to the lower end of therear leg set 12.

As shown in FIGS. 5 to 9, the locking mechanism 4 comprises a lockingpin 41 and a locking hole 42, the locking pin 41 being disposed on thehandlebar set 15, the locking hole 42 being disposed in the slider 16,the frame 1 being in a locked state when the locking pin 41 is insertedinto the locking hole 42, and the frame 1 being in an unlocked statewhen the locking pin 41 is disengaged from the locking hole 42. When theframe 1 is in the locked state, since the locking pin 41 located in thehandlebar set 15 is inserted into the locking hole 42 of the slider 16,the slider 16 cannot be slid. In this case, the frame 1 cannot collapsefrom an unfolded state to a folded state, thus preventing the frame 1from unexpectedly collapsing and injuring the baby when the stroller isused. When the frame 1 is in the unlocked state, the locking pin 41 isdisengaged from the locking hole 42, and the slider 16 can slide alongthe length of the handlebar set 15. In this case, the frame 1 cancollapse from an unfolded state to a folded state. In addition, thelocking mechanism 4 of the present invention has a simple structure andfunctions reliably.

The locking pin 41 comprises a stopper portion 411 and a locking portion412 that extends laterally from the stopper portion 411. The lockingportion 412 is inserted into the locking hole 42, and the stopperportion 411 is limited to one side of the locking hole 42. The stopperportion 411 is configured to limit the position of the locking portion412 to prevent the locking portion 412 from being excessively inserted.

The locking mechanism 4 further comprises a spring 43, a cylindricalsupport portion 4121 is provided in a central portion of the lockingportion 412, the locking portion 412 is recessed with an accommodatingspace 4122.

The handlebar set 15 comprises an upper handlebar set 151 and a lowerhandlebar set 152, and a joint head 153 between the upper handlebar set151 and the lower handlebar set 152, and the upper handlebar set 151 canbe rotated relative to the lower handlebar set 152 by the joint head153.

The lower handlebar set 152 comprises an insert 1521, one end of thespring 43 extends into the accommodating space 4122 and abuts againstthe cylindrical support portion 4121, and the other end of the spring 43abuts against the insert 1521. By providing the spring 43, the lockingmechanism 4 has a function of automatic restoration. When the frame 1 isopened from a folded state to an unfolded state, the locking pin 41 isautomatically inserted into the locking hole 42 by the elastic force ofthe spring 43. Thus, the frame 1 can be automatically locked, withoutthe need of manual locking. This prevents any adverse consequences whena user forgets to lock a stroller when using it.

The locking mechanism 4 further comprises a linkage member. One end ofthe linkage member is connected to the locking pin 41, and the other endof the linkage member is connected to the joint head 153. In anembodiment, the linkage member is a pull cord, in particular a steelcord 60 (see FIG. 9B), also referred to as a pull cord 60, one end ofthe steel cord 60 being connected to the locking pin 41, the other endof the steel cord 60 being connected to the joint head 153. To fold theframe 1, it is only necessary to rotate the upper handlebar set 151,and, at the same time, the joint head 153 rotates, thereby driving thesteel cord to move, so that the locking pin 41 is disengaged from thelocking hole 42 and the spring 43 is in a compressed state. In thiscase, the frame 1 is in the unlocked state, and can be smoothlycollapsed from an unfolded state to a folded state. During the folding,gravity assists in the folding movement.

To open the frame 1, first unfold the other parts of the frame 1 inturn, and then rotate the upper handlebar set 151 in the oppositedirection, and the joint head 153 is simultaneously rotated. The lockingpin 41 is inserted into the locking hole 42 by the elastic force of thespring 43, so that the frame 1 is in the locked state when unfolded.

As shown in FIG. 1, the handlebar set 15 further comprises a connectingmember 154 that is connected to the lower portion of the lower handlebarset 152, in particular to the lower end of the lower handlebar set 152.The middle portion of the rear leg set 12 is rotatably connected to theconnecting member 154 via its connection with the lower handlebar set.The rear portion of the seat set 13, in particular the rear end of theseat set 13, is rotatably connected to the connecting member 154. Inother words, the rotatable connection between the middle portion of therear leg set 12 and the rear portion of the seat set, in particular therear end of the seat set 13 occurs via the lower portion of thehandlebar set 15, in particular the lower end of the handlebar set 15and via the connecting member 154.

As shown in FIG. 10, the frame 1 further comprises a backrest bar 91,the backrest bar 91 being connected to the connecting member 154. Thebackrest bar 91 is used for mounting a baby's back cushion. Theconnecting member 154 is provided with a plurality of tooth portions1541. The backrest bar 91 can be rotated to engage with the differenttooth portions 1541, thereby adjusting the angle of the backrest cushionso that the baby feels more comfortable when sitting in the stroller.

FIG. 12 is a schematic view showing an example embodiment of theconnection relationship between the front leg set, the rear leg set, andthe side armrest according to the present invention, wherein the upperportion of the rear leg set 12 is rotatably connected to the upperportion of the front leg set 11, and the upper portion of the front legset 11 is not rotatably connected to the lower portion of the sidearmrest 14. In one embodiment, the upper end of the rear leg set 12 isrotatably connected to the upper end of the front leg set 11, and theupper end of the front leg set 11 is not rotatably connected to thelower end of the side armrest 14.

FIG. 13 is a schematic view showing a third embodiment of the connectionrelationship between the front leg set, the rear leg set, and the sidearmrest according to the present invention, wherein the upper portion ofthe front leg set 11 is rotatably connected to the lower portion of theside armrest 14, and the upper portion of the front leg set 11 is notrotatably connected to the upper end of the rear leg set 12. In anembodiment, the upper end of the front leg set 11 is rotatably connectedto the lower end of the side armrest 14, and the upper end of the frontleg set 11 is not rotatably connected to the upper end of the rear legset 12.

While the present invention has been specifically described above withreference to preferred embodiments, it should be understood that saidembodiments are not intended to limit the present invention and thatthose of ordinary skill in the art can make various modifications,equivalent substitutions, and improvements without departing from thespirit and scope of the present invention as defined by the claims.

As shown in FIGS. 14 to 20, a further embodiment of a collapsiblestroller frame, in particular an automatically collapsible strollerframe of the present invention comprises: a front leg set 11, the frontleg set 11 comprising a front leg bar 111; and a rear leg set 12, therear leg set 12 comprising a rear leg bar 121.

The stroller frame further comprises a handlebar set 15. The handlebarset 15 is provided with a slider 16 that is slidable along its axialdirection. In one embodiment, the handlebar set 15 comprises a lowerhandlebar tube 152 and a U-shaped upper handlebar tube 151 that isrotatably disposed at an upper end of the lower handlebar tube 152, thelower handlebar tube 152 being provided with the slider 16 that isslidable along its axial direction.

A locking assembly 4 is provided between the handlebar set 15 and theslider 16 for locking or unlocking the slider 16, the handlebar set 15is hinged to the rear leg bar 121, and a transmission member 14 ishinged between the slider 16 and the rear leg bar 121 or the front legbar 111.

In one embodiment, the locking assembly 4 is provided between the lowerhandlebar tube 152 and the slider 16 for locking or unlocking the slider16 so that it is fixed to the lower handlebar tube 152 or is slidable inthe axial direction of the lower handlebar tube 152. The lower handlebartube 152 is hinged to the rear leg bar 121. For example, the lower endof the lower handlebar tube 152 is hinged to the rear leg bar 121, inparticular to the middle portion of the rear leg bar 121. A transmissionmember 14 is hinged between the slider 16 and the upper portion of therear leg bar 121 or the upper portion of the front leg bar 111.

The upper end of the front leg bar 111 is hinged to the lower end of thetransmission member 14 and/or the upper end of the rear leg bar 121. Inone embodiment, as shown in FIG. 20, the upper end of the front leg bar111, the lower end of the transmission member 14, and the upper end ofthe rear leg bar 121 are coaxially hinged.

The stroller frame further comprises an elastic member 43, the elasticmember 43 being a spring or a rubber band. The elastic member 43 isassociated with the front leg bar 111 and the rear leg bar 121 such thatwhen the stroller frame collapses, the front leg bar 111 and the rearleg bar 121 are automatically brought close together under the elasticpulling of the elastic member 43, thereby completing the collapsing

In one embodiment, the elastic member 43 is disposed between the frontleg bar 111 and the rear leg bar 121 such that when the stroller framecollapses, the front leg bar 111 and the rear leg bar 121 areautomatically brought close together under the elastic pulling of theelastic member 43, thereby completing automatic collapsing. When theupper handlebar tube 151 is rotated relative to the lower handlebar tube152, the locking assembly 4 unlocks the slider 16, and the front leg bar111 and the rear leg bar 121 are automatically brought close together bythe elastic pulling of the elastic member 43. At the same time, thetransmission member 14 drives the slider 16 to slide down the axialdirection of the lower handlebar tube 152 to drive the lower handlebartube 152 towards the direction of the rear leg bar 121, therebycollapsing the whole stroller frame, which is very fast and convenient.Gravity and the force from the elastic member 7 cooperate during thefolding movement.

The stroller frame further comprises a seat set 13, the seat set 13being hinged to the front leg bar 111, the seat set 13 being hinged tothe lower end of the lower handlebar tube 152, in particular via aconnecting base 154.

In an embodiment, the front portion of the seat set 13 is hinged to amiddle portion of the front leg bar 111. The rear end of the seat set 13is hinged to the lower end of the lower handlebar tube 152, inparticular via a connecting base 154. The front end of the elasticmember 43 is fixed to the seat set 13. The elastic member 43 may befixed to the front portion or to a middle portion of the seat set. Theelastic member 43 acts between the seat set 13 and the rear leg bar 121.When the stroller collapses, the front leg bar 111 and the rear leg bar121 are automatically brought together, and the seat set 13 is alsorotated forward to move towards the front leg bar 111. It will be clearto the skilled person that the elastic member 43 can be arrangedslightly differently, while maintaining the same functionality ofpulling the front leg bar 111 and the rear leg bar 121 toward oneanother during the folding movement.

The stroller further comprises a backrest set 9, the backrest set 9comprising a U-shaped backrest bar 91, the connecting base 154 beingconnected to the lower end of the lower handlebar tube 152 which in turnis hinged to the middle portion of the rear leg bar 121. The end of thebackrest bar 91 is hinged to the connecting base 154.

The rear end of the elastic member 43 is directly or indirectly fixed tothe connecting base 154. For instance, the rear end of the elasticmember 43 may be connected to a transverse rod which interconnects theright and left connecting base 154. Certainly, the rear end of theelastic member 43 is also directly fixable to the rear leg bar 121. Whenthe stroller collapses, the front leg bar 111 and the rear leg bar 121are automatically brought together, driving the connecting base 154 andthe backrest bar 91 to, following the lower handlebar tube 152, movetowards the rear leg bar 121.

The locking assembly 4 comprises a locking pin 41 provided in the lowerhandlebar tube 152 and a locking hole 42 provided in the slider 16, andthe locking pin 41 can penetrate the lower handlebar tube 152 and beelastically engaged in the locking hole 42. When the locking assembly 4is in the locked state, the locking pin 41 in the lower handlebar tube152 is engaged in the locking hole 42 of the slider 16, so that theslider 16 is not slidable relative to the lower handlebar tube 152. Inthis case, the stroller frame is not collapsible from an unfolded stateto a folded state, and thus the stroller frame does not unexpectedlycollapse and injure the baby when the stroller is used. When the lockingassembly 4 is in the unlocked state, the locking pin 41 is disengagedfrom the locking hole 42, and the slider 16 is slidable along the axialdirection of the lower handlebar tube 152. In this case, the strollerframe is collapsible from an unfolded state to a folded state. Inaddition, the locking assembly 4 of the present invention has a simplestructure and operates reliably.

A rotating base 153 is provided between the lower handlebar tube 152 andthe upper handlebar tube 151, and a linkage member, in particular a pullcord (60, see FIG. 19B) is disposed between the rotating base 153 andthe locking pin 41. To fold the stroller frame, it is only necessary torotate the upper handlebar tube 151 so that it rotates relative to thelower handle bar tube 152 and is folded. In this case, the rotating base153 rotates at the same time, thereby driving the pulling cord to moveso that the locking pin 41 is disengaged from the locking hole 42. Inthis case, the locking assembly 4 is in an unlocked state, and thestroller frame is automatically collapsible from an unfolded state to afolded state. When it is necessary to unfold the stroller frame, firstunfold the other parts of the stroller frame in turn, and then rotatethe upper handlebar tube 151 in the opposite direction, and the rotatingbase 153 rotates at the same time. The locking pin 41 is reset by theelastic force and inserted into the locking hole 42 so that the lockingassembly 4 is locked when the stroller frame is an unfolded state.

The upper handlebar tube 151 is provided with an unlocking member 50 forunlocking or locking the upper handlebar tube 151 so that it isrotatable or fixed relative to the lower handlebar tube 152. To fold thestroller frame, it is only necessary to operate the unlocking member 50so that the upper handlebar tube 151 is unlocked and operate it torotate relative to the lower handlebar tube 152 and fold, therebyrealizing automatic collapsing. When the stroller frame is unfolded, theunlocking member 50 locks the upper handlebar tube 151 so that it is notrotatable relative to the lower handlebar tube 151.

Another embodiment of the present invention as shown in FIG. 21 differsfrom the above-mentioned configuration only in that the upper end of thefront leg bar 111, the lower end of the transmission member 14, and theupper end of the rear leg bar 121 are not coaxially hinged. Instead, theupper end of the front leg bar 111 is hinged to the upper end of therear leg bar 121 and is not hinged to the lower end of the transmissionmember 14. Although the connection relationship of the front leg bar111, the transmission member 14, and the rear leg bar 121 which may beslightly different from that of other example embodiments, it is alsopossible to achieve all the technical effects of the same.

A further embodiment of the present invention as shown in FIG. 22differs from the above-mentioned configuration only in that the upperend of the front leg bar 111, the lower end of the transmission member14, and the upper end of the rear leg bar 121 are not coaxially hinged.Instead, the upper end of the front leg bar 111 is hinged to the lowerend of the transmission member 14 and is not hinged to the upper end ofthe rear leg bar 121. Although the connection relationship of the frontleg bar 111, the transmission member 14, and the rear leg bar 121 isslightly different from that of some example embodiments of the presentinvention, it is also possible to achieve all the technical effects ofthe same.

When the present invention is used, the stroller frame is unfolded to astate shown in FIG. 14 or FIG. 15 (the unfolding operation still needsto be manually performed). To collapse the stroller, it is onlynecessary to operate the unlocking member 50 so that the upper handlebartube 151 is unlocked and operate it to rotate relative to the lowerhandlebar tube 152 and fold. In this case, the rotating base 153 rotatesat the same time, thereby driving the pulling cord to move so that thelocking pin 41 is disengaged from the locking hole 42. In this case, thelocking assembly 4 is in an unlocked state.

As shown in FIG. 16, under the elastic pull of the elastic member 43,the front leg bar 111 and the rear leg bar 121 are automatically broughttogether, and the seat set 13 also rotates forward to move towards thefront leg bar 111. At the same time, the transmission member 14 drivesthe slider 16 to slide down the axial direction of the lower handlebartube 152, thereby driving the lower handlebar tube 152 to move towardsthe rear leg bar 121. The connecting base 154 and the backrest bar 91are rotated to, following the lower handlebar tube 152, move towards therear leg bar 121, thereby collapsing the whole stroller frame, which isvery quick and convenient.

As shown in FIG. 17, the collapsed stroller frame, supported by thefront and rear castors, stands upright. Therefore, it is possible toplace the collapsed stroller upright without the need of laying it flat,thereby saving floor space.

The term “middle portion” as used herein, for instance in connectionwith the front leg set and the rear leg set is to be interpreted broadlyand refers to the portion between the opposing ends thereof.

While the present invention has been particularly described above withreference to preferred embodiments, it should be understood that saidembodiments are not intended to limit the present invention and thatthose of ordinary skill in the art can make various modifications,equivalent substitutions, and improvements without departing from thespirit and scope of the present invention as defined by the claims. Assuch, the foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the embodiments to the precise forms disclosed. Many modificationsand variations are possible in view of the above teachings. Theembodiments were chosen and described in order to best explain theprinciples of the embodiments and its practical applications, to therebyenable others skilled in the art to best utilize the various embodimentswith various modifications as are suited to the particular usecontemplated.

Unless the context clearly requires otherwise, throughout thedescription, the words “comprise,” “comprising,” and the like are to beconstrued in an inclusive sense as opposed to an exclusive or exhaustivesense; that is to say, in a sense of “including, but not limited to.”Words using the singular or plural number also include the plural orsingular number respectively. Additionally, the words “herein,”“hereunder,” “above,” “below,” and words of similar import refer to thisapplication as a whole and not to any particular portions of thisapplication. When the word “or” is used in reference to a list of two ormore items, that word covers all of the following interpretations of theword: any of the items in the list, all of the items in the list and anycombination of the items in the list.

Although certain presently preferred implementations of the embodimentshave been specifically described herein, it will be apparent to thoseskilled in the art to which the embodiments pertains that variations andmodifications of the various implementations shown and described hereinmay be made without departing from the spirit and scope of theembodiments. Accordingly, it is intended that the embodiments be limitedonly to the extent required by the applicable rules of law.

1-63. (canceled)
 64. A stroller system, comprising: a collapsible framewith a bottom and a top, the collapsible frame including, a front legset, a rear leg set with an upper portion a middle portion, and a lowerportion, a seat set, a side armrest with an upper and lower portion, ahandlebar set with an upper portion and a lower portion, and a slider,configured to slide along the handlebar set upper portion, wherein theupper portion of the side armrest is rotatably connected to the slider,wherein the lower portion of the side armrest is rotatably connected tothe front leg set and to the rear leg set; the rear leg set beingrotatably connected to the lower portion of the handlebar set, whereinat least one of the rear leg set and the side armrest is rotatablyconnected to the front leg set; the front leg set being rotatablyconnected to the seat set; the seat set being rotatably connected to thelower portion of the handlebar set, via a connecting member; a frontwheel assembly, disposed at a front portion of the bottom of thecollapsible frame; a rear wheel assembly, disposed at a rear portion ofthe bottom of the frame; and a locking mechanism, disposed between thehandlebar set and the slider, the locking mechanism being configured tolock the frame in an unfolded state.
 65. The stroller system of claim 1,wherein the lower portion of the side armrest is rotatably connected tothe upper portion of the rear leg set, the rear leg set being rotatablyconnected to the lower portion of the handlebar set, the middle portionof the rear leg set being rotatably connected to the lower portion ofthe handlebar set, at least one of the upper end of the rear leg set andthe lower end of the side armrest being rotatably connected to the upperend of the front leg set, and wherein the middle portion of the frontleg set is rotatably connected to the seat set.
 66. The stroller systemof claim 1, wherein the rear end of the seat set is rotatably connectedto the lower end of the handlebar set.
 67. The stroller system of claim1, wherein the locking mechanism includes a locking pin and a lockinghole, the locking pin being disposed on the handlebar set, the lockinghole being disposed in the slider, the frame being in a locked statewhen the locking pin is inserted into the locking hole, and wherein theframe is in an unlocked state when the locking pin is disengaged fromthe locking hole.
 68. The stroller system of claim 1, wherein thehandlebar set includes an upper handlebar set and a lower handlebar set,and a joint head disposed between the upper handlebar set and the lowerhandlebar set.
 69. The stroller system of claim 5, wherein the lockingmechanism further comprises a spring, a central portion of a lockingportion is provided with a cylindrical support portion, the lockingportion is recessed with an accommodating space, the lower handlebar setcomprises an insert, one end of the spring extends into theaccommodating space and abuts against the cylindrical support portion,and the other end of the spring abuts against the insert.
 70. Thestroller system of claim 6, wherein the locking mechanism furtherincludes a linkage member, with a steel pull cord, wherein a first endof the linkage member is connected to the locking pin, and a second endof the linkage member being connected to the joint head.
 71. Thestroller system of claim 7, wherein the handlebar set the connectingmember is connected to the lower portion of the handlebar set, themiddle portion of the rear leg set is rotatably connected to theconnecting member via the lower portion of the handlebar set, and therear portion of the seat set is rotatably connected to the connectingmember.
 72. The stroller system of claim 1, wherein the upper end of thefront leg set, the upper end of the rear leg set, and the lower end ofthe side armrest are coaxially hinged.
 73. The stroller system of claim1, wherein the middle portion of the front leg set is rotatablyconnected to the seat set.
 74. A stroller system, comprising: a framewith a top and a bottom, the frame configured to be collapsible from anunfolded state to a folded state, the frame including, a front leg set,a rear leg set with an upper and a lower portion, a seat set, ahandlebar set with an upper and a lower portion, wherein the upperportion of the rear leg set is rotatably connected to the lower portionof the handlebar set; wherein the upper end of the rear leg set isrotatably connected to the upper end of the front leg set, and the rearleg set further being rotatably connected to the lower portion of thehandlebar set; wherein the seat set is connected to the lower portion ofthe handlebar set, the front leg set and the rear leg set; a front wheelassembly disposed at a front portion of the bottom of the frame, thefront wheel assembly including two front wheels, a rear wheel assembly,disposed at a rear portion of the bottom of the frame, the rear wheelassembly including two rear wheels, and a locking mechanism disposed onthe handlebar set, the locking mechanism configured to lock the frame inan unfolded state, wherein the handlebar set upper portion is U-shaped,and a joint head is disposed between the U-shaped upper handlebarportion and the lower handlebar portion, wherein the U-shaped upperhandlebar portion is pivotable relative to the lower handlebar portionand includes an unlocking member for unlocking the U-shaped upperhandlebar portion so that it is rotatable and a locking member forlocking the U-shaped upper handlebar set so that it is fixable relativeto the lower handlebar set, wherein the locking member includes alocking pin and a locking hole located in a portion of the frame belowthe joint head, the frame configured in a locked state when the lockingpin is in an inserted position into the locking hole, and the framebeing in an unlocked state when the locking pin is disengaged from thelocking hole, wherein the locking mechanism further comprises a linkagemember, one end of the linkage member being connected to the lockingpin, the other end of the linkage member being connected to the jointhead, wherein the linkage member is pulled by a forward rotation of theU-shaped upper handlebar set relative to the lower handlebar set,thereby pulling the locking pin from the locking hole and unlocking thelocking mechanism, causing the stroller to collapse to a folded state,wherein in the folded state the collapsed stroller frame stands upright.75. The stroller according to claim 11, wherein the middle portion ofthe front leg set being rotatably connected to the seat set.
 76. Thestroller according to claim 11, wherein the rear end of the seat setbeing rotatably connected to the lower end of the handlebar set.
 77. Thestroller according to claim 11, wherein the locking mechanism furthercomprises a spring, a central portion of a locking portion is providedwith a cylindrical support portion, the locking portion is recessed withan accommodating space, the lower handlebar set comprises an insert, oneend of the spring extends into the accommodating space and abuts againstthe cylindrical support portion, and the other end of the spring abutsagainst the insert.
 78. The stroller according to claim 11, wherein theupper end of the front leg set, the upper end of the rear leg set, andthe lower end of the side armrest are coaxially hinged.
 79. Acollapsible stroller frame, comprising: a front leg set, the front legset comprising a front leg bar, a rear leg set, the rear leg setcomprising a rear leg bar, a handlebar set being provided with a sliderthat is slidable along its axial direction, a locking assembly beingprovided between the handlebar set and the slider for locking orunlocking the slider , the handlebar set being hinged to the rear legbar, a transmission member being hinged between the slider and the rearleg bar or the front leg bar, and an elastic member being associatedwith the front leg bar and the rear leg bar such that when the strollerframe collapses, the front leg bar and the rear leg bar are broughtclose together under the elastic pulling of the elastic member , therebycompleting the collapsing.
 80. The collapsible stroller frame accordingto claim 16, the handlebar set comprising a lower handlebar tube and anupper handlebar tube that is rotatably disposed at an upper end of thelower handlebar tube , the lower handlebar tube being provided with theslider that is slidable along its axial direction, the locking assemblybeing provided between the lower handlebar tube and the slider , thelower handlebar tube being hinged to the rear leg bar.
 81. Thecollapsible stroller frame according to any of claims 16, wherein theupper handlebar tube is U-shaped, the lower end of the lower handlebartube being hinged to the rear leg bar , in particular to a middleportion thereof.
 82. The collapsible stroller frame according to claim16, wherein the stroller frame is automatically collapsible, wherein thefront leg bar and the rear leg bar are automatically brought closetogether under the elastic pulling of the elastic member , therebycompleting the collapsing.
 83. The collapsible stroller frame accordingto claim 16, further comprising a seat set , the seat set being hingedto the front leg bar , the seat set being hinged to the lower end of thelower handlebar tube , in particular via a connecting base.
 84. Thecollapsible stroller frame according to claim 20, the front end of theelastic member being fixed to the seat set, in particular fixed to afront portion or to a middle portion of the seat set.
 85. Thecollapsible stroller frame according to claim 21, the front portion ofthe seat set being hinged to the middle portion of the front leg bar ,the rear end of the seat set being hinged to the lower end of the lowerhandlebar tube, in particular via the connecting base.
 86. Thecollapsible stroller frame according to claim 16, wherein the connectingbase being connected to the lower end of the lower handlebar tube whichis hinged to the middle portion of the rear leg bar.
 87. The collapsiblestroller frame according to claim 23, further comprising a backrest set,the backrest set comprising a U-shaped backrest bar, the end of thebackrest bar being hinged to the connecting base.
 88. The collapsiblestroller frame according to claim 24, wherein the rear end of theelastic member is directly or indirectly fixed to the connecting base ordirectly fixed to the rear leg bar.
 89. The collapsible stroller frameaccording to claim 16, wherein the locking assembly comprises a lockingpin disposed in the lower handlebar tube and a locking hole disposed inthe slider, and the locking pin can penetrate the lower handlebar tubeand be elastically engaged in the locking hole, wherein a rotating baseis disposed between the lower handlebar tube and the upper handlebartube , and a pull cord is disposed between the rotating base and thelocking pin.
 90. The collapsible stroller frame according to claim 16,wherein the upper handlebar tube is provided with an unlocking memberfor unlocking the upper handlebar tube so that it is rotatable andlocking the upper handlebar tube so that it is fixable relative to thelower handlebar tube.
 91. The collapsible stroller frame according toclaim 16, wherein the elastic member is a spring or rubber band.